Assessment of heart rate variability, baroreceptor sensitivity and its association with serum catestatin in vertigo patients: An observational study

Background: Vertigo, characterized by an illusion of motion, affects 5% of the population. The vestibular system regulates blood pressure during postural changes via the vestibulo-sympathetic reflex, which gets activated by linear acceleration, stimulating otolith organs, increasing blood pressure transiently via sympathetic discharge. Catestatin regulates cardiac function, enhancing baroreflex sensitivity, increasing cardiac vagal, reducing sympathetic activity and modulating blood pressure acting on the nucleus tractus solitarius. Aim: The study aimed to evaluate heart rate variability (HRV), baroreceptor sensitivity (BRS) and their association with serum catestatin levels in vertigo subjects. Methods: Seventy-three newly diagnosed vertigo patients were recruited. HRV parameters and BRS were assessed to evaluate autonomic function. Serum catestatin levels were measured using an enzyme-linked immunosorbent assay. Correlation analysis was done to investigate the relationship between serum catestatin and HRV indices. Results: The time-domain HRV parameters, mean RR intervals and mean heart rate (HR) indicated resting parasympathetic activity in the study group. Low-frequency power was reduced in vertigo patients, indicating diminished sympathetic activity. High-frequency power was elevated, indicating marked cardiac vagal dominance. Total power showed reduced autonomic tone in the vertigo group. Sympathovagal balance shifted towards increased vagal activity. BRS was reduced, leading to impaired autonomic balance. Serum catestatin levels were at the lower range of normal, expressing an association with autonomic parameters and maintaining blood pressure homeostasis. Conclusion: Serum catestatin plays a compensatory role in maintaining blood pressure in early-stage vertigo. Study reports that autonomic imbalance, characterized by increased vagal tone and reduced sympathetic drive, is evident in the early stages of vertigo, predisposing patients to orthostatic intolerance.